1. Field of the Invention
The present invention relates to the technical field of a disk drive device which is suitable for use as an optical disk device for performing a recording operation and/or a reproducing operation on an optical disk, such as a compact disk (CD) and a digital versatile disk (DVD).
2. Description of the Related Art
The applicant of the present invention previously filed an application for a tray-system optical disk device 1, such as that shown in FIGS. 35 to 42, as an optical disk device which is one example of a disk drive device.
As shown in FIG. 35, an optical disk 1, such as a CD or a DVD, which is a disk-shaped recording medium, is placed horizontally inside a recess 3 formed in the top surface of a tray body 2a of a disk tray 2. Then, when a tray front panel 2b of the disk tray 2 is lightly pushed in the direction of direction a, a loading switch (not shown) is turned on. A loading mechanism unit 27 (described later) causes the disk tray 2 to be horizontally drawn into a disk device body 6 of an optical disk device 5 from a tray entering-and-exiting opening 4 in a front panel 6a in the direction of arrow a which is the loading direction, as shown in FIG. 36. As described below, this causes the optical disk 1 to be automatically loaded horizontally onto a disk table of a spindle motor.
In the structure, after the loading, for example, a recording command signal and/or a reproducing command signal from a host computer causes the optical disk 1 to be rotationally driven at a high speed by the spindle motor in order for an optical pickup, which is a data pickup means, to record and/or reproduce data onto/from the optical disk 1. Then, after the recording operation and/or the reproducing operation on the optical disk 1, when an eject button 7 on the front panel 6a is pushed, the loading mechanism unit 27 (described later) causes the disk tray 2 to be automatically unloaded out of the disk device body 6 from the tray entering-and-exiting opening 4 in the direction of arrow b which is the unloading direction, as shown in FIG. 35.
As shown in FIGS. 35 to 42, the horizontal tray body 2a of the disk tray 2 and the vertical tray front panel 2b, which is at right angles to the directions of arrows a and b, are formed of, for example, synthetic resin. From the center of the recess 3 of the tray body 2a to the back end (that is, the end towards which the arrow a points), a slot-shaped bottom surface opening 8 is formed along a tray centerline P1 which is horizontal to the directions of arrows a and b which are the loading and unloading directions, respectively. The disk tray 2 is constructed so as to be actuated by a tray moving mechanism (not shown) of a loading mechanism in such a manner as to horizontally move into and out of the disk device body 6 in the directions of arrows a and b. Four disk holding sections 3a are mounted to four corresponding locations of the outer periphery of the recess 3 of the disk tray 2 so as to be rotationally adjustable. The disk-holding sections 3a are constructed so that, when the optical disk device 5 is used in a vertical posture, they can hold the optical disk 1 inserted vertically into the recess 3.
In the structure, a shallow, almost box-shaped chassis 14, which is formed of, for example, synthetic resin, is provided inside the disk device body 6. An ascending-and-descending frame 16, which is formed of, for example, synthetic resin or sheet metal, is mounted inside a large, substantially rectangular opening 14b formed in a bottom portion 14a of the chassis 14. A total of four substantially gourd-shaped insulators 19 and insulators 20 are mounted to the ascending-and-descending frame 16, the two insulators 19 being mounted at the left and right sides of a back end portion 16a, and the two insulators 20 being mounted at the left and right sides of a front end portion 16b. The insulators 19 and the insulators 20 are shock absorbers formed of resilient material such as rubber. The pair of left and right insulators 19 mounted to the back end portion 16a of the ascending-and-descending frame 16 are mounted to the upper portion of the back end side of the bottom portion 14a of the chassis 14 by setscrews 21 which are inserted into the centers thereof. The left and right insulators 20 mounted to the front end portion 16b of the ascending-and-descending frame 16 are mounted to the lower portion of the left and right sides of an ascending-and-descending actuation frame 23 by setscrews 22 which are inserted into the centers thereof. By the ascending-and-descending actuation frame 23, the front end portion 16b of the ascending-and-descending frame 16 is actuated so as to move upward and downward in the directions of arrows c and d through the pair of left and right insulators 20 by an upward rotational motion and a downward rotational motion on the pair of left and right insulators 19 at the back end portion 16a serving as rotational fulcra.
The loading mechanism unit 27 is mounted to the upper portion of the front end side of the bottom portion 14a of the chassis 14. The loading mechanism unit 27 comprises a cam lever 34 which is rotationally driven by a loading motor 28 through a belt transmission mechanism 29 and a gear transmission mechanism 30. The ascending-and-descending actuation frame 23 is mounted at the front-end-side left and right sides of the opening 14b of the chassis 14 by a pair of left and right support pins 24, one being provided at the left side and the other at the right side of the back end of the ascending-and-descending actuation frame 23. The ascending-and-descending actuation frame 23 is mounted so as to be rotatable upward and downward. A pair of left and right ascending-and-descending guide pins 25 are mounted closer to the front side than the pair of left and right pair of support pins 24, one at the left side and one at the right side of the ascending-and-descending actuation frame 23. A cam driven pin 36 which is mounted to substantially the center portion of the front end of the ascending-and-descending actuation frame 23 is inserted inside a cam groove 35 of the cam lever 34.
When loading, the loading motor causes the disk tray 2 to be horizontally drawn in the direction of arrow a to a loading position (shown in FIG. 35) inside the optical disk device 5 from an unloading position (shown in FIGS. 36 and 38) outside the optical disk device 5. Thereafter, as shown in FIG. 39, by the cam groove 35 of the cam lever 34 which is rotationally driven in the direction of arrow cxe2x80x2, the cam driven pin 36 at an end of the ascending-and-descending actuation frame 23 is actuated upward in the direction of arrow c that is the upward direction. Through the insulators 20, the ascending-and-descending actuation frame 23 causes the ascending-and-descending frame 16 to be actuated upward in the direction of arrow c to an ascended position where the ascending-and-descending frame 16 is horizontally positioned (shown in FIG. 38) from a descended position where the ascending-and-descending frame 16 is tilted obliquely downward (shown in FIG. 37), with the pair of left and right insulators 19 serving as centers.
In the structure, when the disk tray 2 is unloaded, the component parts move in a direction opposite to that when the disk tray 2 is loaded. By the cam groove 35 of the cam lever 34 which is rotationally driven in the direction of arrow dxe2x80x2 (see FIG. 39), the cam driven pin 36 is driven downward in the direction of arrow d which is the downward direction. Through the left and right insulators 20, the ascending-and-descending actuation frame 23 causes the ascending-and-descending frame 16 to be actuated downward in the direction of arrow d from the ascended position (shown in FIG. 38) to the descended position (shown in FIG. 37), with the pair of left and right insulators 19 as centers. Thereafter, the disk tray 2 is pushed out in the direction of arrow b from the loading position (shown in FIGS. 36 and 38) inside the optical disk device 5 to the unloading position (shown in FIGS. 35 and 37) outside the optical disk device 5. The disk tray 2 is constructed in such a way as to be loaded and unloaded by actuation in the directions of arrows a and b through a rack (not shown) by rotationally actuating a pinion 31 disposed inside the gear transmission mechanism 30 at the loading mechanism unit 27 in the forward and reverse directions.
The ascending-and-descending frame 16 which is the unit base of an optical pickup unit 38 which serves as a data pickup unit is formed with a substantially rectangular frame-like shape. A spindle motor 39 is vertically installed on the top portion of the front end portion 16b of the ascending-and-descending frame 16. A disk table 40, which is formed of a magnetic material, such as metal, is affixed horizontally to the upper end of a motor shaft 39a. A centering guide 40a to which a center hole 1a of the optical disk 1 is fitted is integrally formed at the center of the top portion of the disk table 40. An optical pickup 41, which serves as a data pickup, is horizontally installed behind the spindle motor 39, inside the substantially rectangular opening 16c which is formed at the inner side of the ascending-and-descending frame 16. The optical pickup 41 has a sled 43 on which an objective lens 42 is installed. An optical block, which transmits and receives laser beams to and from the objective lens 42, is integrally mounted to a side surface of the sled 43. An objective lens actuator section 44 which curves outward into a convex shape towards the optical disk 1 is installed on the sled 43. The objective lens 42 is incorporated at the top portion of the objective lens actuator section 44 by a biaxial actuator.
A sled moving mechanism 47 is mounted to the top portion of a side of the back end portion 16a of the ascending-and-descending frame 16 in order to move the sled 43 to which the optical pickup unit 38 is installed in a straight line in the directions of arrows a and b along a pair of left and right guide shafts 45 and 46, which serve as a guide main shaft 45 and a guide sub-shaft 46, respectively. The sled moving mechanism 47 comprises a pinion 50, which is rotationally driven in the forward and reverse directions by a sled drive motor 48 through a gear train 49, and a rack 51 which is mounted to one side surface of the sled 43 and actuated in a straight line by the pinion 50. The spindle motor 39 and the objective lens 42 are disposed on the tray centerline P1. The objective lens 42 is constructed so as to move in the directions of arrows a and b along the tray centerline P1. A skew adjusting mechanism 57 for adjusting the angle between the guide main shaft 45 and the guide sub-shaft 46 in the vertical direction is installed at the lower portion of the ascending-and-descending frame 16.
A clamper supporting frame 52, which is molded out of, for example, a sheet metal, is provided so as to be horizontally constructed between the top ends of the left and right side plates of the chassis 14 in such a manner as to cross the top portion of the disk tray 2. At a location directly above the disk table 40, a disk damper 53, which is molded out of synthetic resin that is a nonmagnetic material, is supported inside a circular hole 54 formed in the center of the clamper supporting frame 52 so as to be movable upward and downward, towards the left and right, and forward and backward within a certain range. A clamper receiver 52a, which catches a flange 53a which is integrally molded at the outer periphery of the top end of the disk damper 53 from therebelow, is integrally formed at the outer periphery of the circular hole 54 of the clamper supporting frame 52. A disk-shaped magnet 55 is horizontally embedded in the center top portion of the disk damper 53. A top cover 6b, which is molded out of a sheet metal that is a magnetic material and which is disposed so as to extend over the top portion of the damper supporting frame 52, is mounted to the top portion of the chassis 14.
Therefore, as shown in FIG. 38, when, by the disk tray 2, the optical disk 1 has been horizontally loaded inside the disk device body 6 in the direction of arrow a, the ascending-and-descending frame 16 is brought to a horizontal posture as a result of moving upward to the ascended position in the direction of arrow c, the disk table 40 is inserted upward from the bottom surface opening 8 of the disk tray 2, so that the centering guide 40a of the disk table 40 is fitted to the center hole 1a of the optical disk 1 from therebelow. The disk table 40 causes the optical disk 1 to fly upward inside the recess 3 of the disk tray 2, and the disk clamper 53 to fly slightly upward from the flange receiver 52a of the clamper supporting frame 52. At this time, the disk damper 53 is attracted to the disk table 40 which is disposed near the bottom surface of the disk clamper 53 by the magnetic force of attraction of the magnet 55. The optical disk 1 is horizontally chucked to the disk table 40 by the disk clamper 53.
As shown in FIGS. 38 to 42, for example, a recording command signal or a reproduction command signal from a host computer causes the spindle motor 39 to rotationally drive the optical disk 1 at a high speed of, for example, at least 3600 rpm, and the sled moving mechanism 47 to move the sled 43 at the optical pickup 41 in the directions of arrows a and b, thereby causing the objective lens 42 to perform a seeking operation in the directions of arrows a and b along the tray center line P1. Then, the spot of the laser beam which is sent from the optical block irradiates and is focused onto the bottom surface of the optical disk 1 by the objective lens 42. The reflected light is received by the optical block through the objective lens 42 in order to record data onto and/or reproduce data from the optical disk 1.
In the structure, by causing the pinion 50 which is driven in the forward and reverse directions through the gear train 49 by the sled drive motor 48 to actuate the rack 51 in a straight line, the sled moving mechanism 47 causes the sled 43 to move in the directions of arrows a and b along the pair of left and right guide shafts 45 and 46. When, after the recording of data onto and/or the reproduction of data from the optical disk 1, the eject button 7 is pushed, the ascending-and-descending frame 16 moves downward to the descended position in the direction of arrow d, thereby causing the disk table 40 to be unchucked from the disk damper 53, and to separate downward from the optical disk 1, as shown in FIG. 37. As shown in FIG. 37, the optical disk 1 is horizontally placed inside the recess 3 of the disk tray 2, and, as shown in FIG. 35, horizontally unloaded outside of the disk device body 6 in the direction of arrow b.
The increasing of the recording capacity to a large recording capacity (that is, the achievement of high-density recording) of this type of optical disk device is being accelerated, so that people are thinking of various methods to achieve this, such as the method of increasing the precision of each of the component parts, the method of performing highly precise adjustments at the manufacturing stage, and the method of using a structure which is adjustable in real time as a result of utilizing an initial signal of the optical disk 1.
One of the simplest methods to achieve a high recording capacity is the method of making adjustments so that the center of the objective lens 42 coincides with the center of the optical disk 1 by causing the interval between the center of the objective lens 42 of the optical pickup 41 and the center of the guide main shaft 45 used to guide the sled 43, and the interval between the center of the spindle motor 39 and the center of the guide main shaft 45 to match.
However, as shown in FIG. 7, conventionally, while a horizontal motor base 39b disposed at the bottom end of the spindle motor 39 is fitted to and positioned from thereabove at a reference hole 62 and a positioning pin 61 implanted in the ascending-and-descending frame 16, the motor base 39b is screwed to the ascending-and-descending frame 16 with a plurality of setscrews 63 from therebelow, and, using a plate spring, the guide main shaft 45 is pushed at right angles to and positioned at a positioning reference portion 64 which is formed by bending portions of the ascending-and-descending frame 16.
However, this method is a method in which the spindle motor 39 and the guide main shaft 45 are positioned with respect to the ascending-and-descending frame 16. It is not a method for directly adjusting the interval between the center of the objective lens 42 and the center of the guide main shaft 45, and the interval between the center of the spindle motor 39 and the center of the guide main shaft 45. Therefore, due to the shifts between the locations of the positioning pin 61 and the reference hole 62 of the ascending-and-descending frame 16, and the location of the positioning reference section 64, the crossing of the diameter of the guide main shaft 45, and the like, variations occur in the interval between the center of the objective lens 42 and the center of the guide main shaft 45, and the interval between the center of the spindle motor 39 and the guide main shaft 45. When the variations occur, high-density recording and/or reproducing operations cannot be performed on the optical disk 1. In order to decrease such variations, it is necessary to increase the precision with which each of the component parts is formed, thereby resulting in considerably increased costs.
Accordingly, in order to overcome the above-described problems, it is an object of the present invention to provide a disk drive device which is constructed so that the location of the center of a pickup, such as an objective lens, and the location of the center of a disk correspond with high precision in order to increase the capacity of the disk drive device to a high capacity.
To this end, according to the present invention, there is provided a disk drive device which is constructed so that a pickup device for recording data onto and/or reproducing data from a disk-shaped recording medium is guided by a guide main shaft and a guide sub-shaft, to which a pickup mounting frame is mounted, and is moved in a radial direction of the disk. The disk drive device comprises positioning means used for a mounting operation with reference to the guide main shaft as a positioning reference during the mounting of a spindle motor to the pickup mounting frame.
In the disk drive device having the above-described structure, the guide main shaft used for guiding the pickup device for the disk-shaped recording medium is mounted to the pickup mounting frame first. Then, the spindle motor is positioned with respect to the guide main shaft by the positioning means, and is mounted to the pickup mounting frame in order to position the pickup means and the spindle motor with respect to each other with high precision, with the guide main shaft serving as a reference.